The New Deep for King Salmon


by Matt Straw

Great Lakes salmon use the entire water column all year. All of it—right to the bottom. Until a U.S. Geological Survey (USGS) study proved that salmon swam around in the deepest areas of Lake Huron, nobody was aware salmon not only go deeper than 700 feet, they split time between ultimate benthic depths and shallow water every day.

Nobody, that is, except Captain Mark Chmura. When we broke the story in 2008 with research biologist Roger Bergstedt of the USGS, Chmura was already tinkering with specialized Big Jon downriggers to get lures down over 500 feet. Chmura, one of the most successful salmon-tournament anglers of all time, has since used his downdeep strategy to win several major events.

“Fishing deeper than 400 feet isn’t much fun,” Chmura admitted. “But when typical spreads at typical depths aren’t working, you have to ask yourself: Would you rather go down deep and get something or come home with nothing? It’s not necessarily fun to fish deep, but it can be very productive.”

Reeling fish up with a thousand feet of line out is taxing, but that’s just the beginning. “Most of the time, you can only put one lure down there because mixing currents will tie two downrigger cables into knots, even if you troll straight as an arrow,” Chmura warned. Motors burn out trying to lift 24-pound cannonballs even on the specialized, heavy-duty downriggers Chmura helped develop. He’s in the final stages, however, of developing a motor that can “take the heat,” but that’s not the only development helping anglers get deeper than ever before.

Deeper Divers

Matthew Sawrie, president and partner with Torpedo Fishing Products, says his Deep Sea Diver with an aqua-dynamic Torpedo fishing weight attached will go deeper and farther to the side than any other planer diver. Dave Mull and I spent some time on the water with Sawrie on Chmura’s boat last year and he was able to prove the Deep Sea Diver went deeper and farther out with another new product called Smart Troll.

A cylindrical Smart Troll Probe attached to the line just above a downrigger ball or diver-planer sends back a wireless signal to a module on board that delivers it (wirelessly) to a monitor on the dash to deliver data on depth and water temperature. Chmura attached one above a Deep Sea Diver and it told us the rig achieved depths of 400 feet, and we could have gone deeper with larger reels.

“The early morning bite always seems to be a diver bite,” Sawrie said. “With two unweighted high divers and two low divers with Torpedo Weights attached, we can put more divers in the water on each side, covering more of the water column out there away from the boat. These divers can reach unlimited depths with the Torpedo attached. For every 100 feet of line you put out it keeps going down to perpetuity. The deepest you can get a multiple downrigger set down is a few hundred feet without specialized equipment. This revolutionizes fishing because small boats can now get down to fish they couldn’t reach before. The farthest down I’ve fished was 421 feet with 1200 feet of line out. I recommend 30-pound braid but to get the deepest you can fish them on wire on a mediumheavy copper rod.”

The largest Torpedo weight is called the Cuda. “Divers get out to the side by tilting to that side,” Sawrie said. “Diver-planers create a lot of turbulence. With the Cuda on, you’re getting more turbulence because it’s choked or tilted even more than a standard diver, so that increases vibration and range of attraction. The Deep Sea Diver is made of material that’s 15% lighter than standard divers, so it not only gets out farther, it’s a little easier to reel in.”

The long, slender Torpedo Weights impressively remain nose first even when trolling at high speed. At times, wire lines with “monkey balls,” those round, resistant, 6-ounce to 1-pound lead weights off the two corners of the transom outfish everything else, which is especially nice when fishing from a small boat. With Torpedo Weights, we can now stay a little more vertical with 3-way rigs, letting out a little less line to get significantly deeper while putting far less stress on the wire, rod, and connections.

Smart Dividends

The Smart Troll Probe was developed by Darrell Huff of Baltimore, Maryland. “When my boys were young, they took up most of my time on the water,” Huff said. “When they became teenagers and discovered girls, I went out by myself a lot and suddenly I had a lot more time to think. One of the first things I realized was that sonar, charts, and GPS were telling me precisely how deep it was and precisely where I was on the planet, but nothing could tell me precisely how deep my lures were running in Chesapeake Bay.”

The resulting Smart Troll, Chmura says, is very precise. “No matter how experienced you are, it’s guesswork trying to determine how deep rigs are running,” Chmura said. “There’s no guesswork with this. We were trying to figure out how far it would pick up, so we put exorbitant amounts of line out and it still worked. What really shocked me was learning just how far out of the zone currents were taking my downriggers. We were going west one day at 2 mph and the Smart Troll told us the rigs were 172 feet down with over 200 feet of cable 7 out. When we turned around at the same speed, heading east into the current, we were only 114 feet down with the same amount of cable out. It’s so nice to be able to constantly monitor actual depth so you can stay in the zone.”

Smart Troll also led Chmura to another one-of-a-kind discovery. “I found out that equal lengths of leadcore and wire achieve the same depths,” he said. “Wire with nothing on it dove to the equivalent depth of leadcore in tests we did. That shocked me. Wire is lighter and people don’t believe it. I let out 7 colors of leadcore and the same length (about 70 feet) of wire and the Smart Troll told us the lures were running at the same depth. People don’t believe it, but this new tool proved to me that it’s true.

“The down temp is accurate, too,” Chmura added. “Using the Smart Troll in tournaments, I put my high diver out with a Smart Troll probe on the port side to search for that all-important 49°F temperature band. When I find it, I adjust line lengths on my low divers until they match that depth. Now, no matter what the currents or wind are doing to us, we can keep adjusting so lures stay in the zone. The Deep Sea Diver with the Cuda attached helps you cover different zones you couldn’t reach before. It takes you down more vertically than horizontally, so it takes you deeper off to the side than anything else. It’s not the sportiest way to catch a fish because it’s so resistant, bringing it in, but it’s deadly effective. They work really well with mono. I fish them on 20-pound Berkley Big Game.”

Not too many trolling aids will get you down there more than 200 feet. “From zero to 100 feet is a cakewalk,” Chmura said. “When you start getting below 200 feet it’s challenging to say in the zone. Kings are using the entire water column to the bottom of the lake, and currents will pick your rigs up and send them way out of the zone. Now you can get four lines way down there and be accurate. It’s a workout, though, if you don’t have the right reel. But Daiwa is working on a new automatic reel for the Great Lakes that will make fishing deep a lot easier.” (Chmura currently uses the Daiwa Tanacom Bull for deep-water fishing, which was designed for ocean duty.)

The only knock on the Smart Troll from Chmura was the lack of a monitor that comes with the system, so anglers need to purchase an app and mount a smart phone or Kindle on the dash to use for a monitor. “My position is I can’t really develop a monitor cheaper than Android can,” Huff said. “I can’t make it cheaper than $100. Didn’t build it for other systems for specific reasons. An iPad, for instance, blocks the ability to send data in the way we need to send it. And it’s a long approval process for downloading apps through them.”

The New Deep

Catching salmon the old-fashioned way (with hook and line) for the USGS back in 2005, Bergstedt surgically implanted his catches with “depth tags” that recorded depth, pressure, and water temperature every 15 minutes for up to three years. Unfortunately, Bergstedt couldn’t fit in the kind of wireless broadcasting technology offered by the Smart Troll, meaning he had to retrieve the tags from fishermen who found them while cleaning fish, and then reported it.

Examining the data from more than 30 recovered tags, Bergstedt discovered king salmon “make a lot of vertical movements,” he said. “Movements to deep water were common and I’ve got to believe they’re down there on business. They’re hunting, and if you put a lure in front of them, they’re probably going to take it.”

Bergstedt reported that one salmon with a tag went to the very bottom of Lake Huron, over 700 feet down. “Tagged salmon were making daily vertical movements of 400 to 600 feet in a matter of minutes,” he said. “These were larger specimens, too. Even in winter, tagged salmon typically held in depths of 400 feet or greater at night, came right to the surface in the morning for a brief period, then turned and went right back to the bottom.”

Chmura said he thinks the discovery of the “new deep,” which basically eliminates all arbitrary depth limits on salmon, “could be the biggest change in perspective the history of trolling for kings. Since we decided to just keep going deeper and deeper one day to see what we could catch off The Shelf (off Manistee, Michigan) out 900 feet of water six years ago, I've been putting customers on 7 or more kings per day when trolling deeper than 300 feet. We catch them deep as 500 feet and we’re still marking kings deeper.”

While it’s challenging to stay “the zone” when dropping and lifting 24- to 30-pound cannonballs through 16 atmospheres of pressure, presentation choices, at least, are simple. Whatever’s working up on top of the shelf will work down there,” Chmura says, “My favorites tend to be glow spoons, like the Stinger Nitro, but I’pull Luhr Jensen J-Plugs, Hot Spot Flashers—anything that’s working top. Glow is a good thing downtown. The Nitro glows for 6 hours on a single charge, so I know it’s working for me without having to pull it all the way back up.”

Chmura often runs things on top while fishing one downrigger “downtown” as he calls it (deep). “I find steelhead on top of those breaks from 300 to 700 feet,” Chmura said. “Currents run just under the surface on those spots, probably reacting to all that water movement down deep. Steelhead often ride those currents in the top 20 feet of the water column, working against the flow like Lake Michigan was just a big river bringing food to them.”

Salmon can dump air, relieving pressure on their swim bladders as they rise. “When we’re fishing downtown, we have to stop the boat for a hookup,” Chmura said. “If we don’t bring them up too fast, we can actually release these fish and they never pop back up on the surface.”

Where, exactly is downtown? “When I tell my first mate we’re going downtown,” Chmura replied, “he knows that means 350 feet or deeper.”

Meet the new deep. Not the same as the old deep.


The Prodigal Depth Charge

This sophisticated depth tag was implanted in a Lake Huron king salmon by Roger Bergstedt of the United States Geological Survey, found by the angler who caught the king, and returned to Bergstadt. It recorded data on temperature, pressure, time of day, and depth every 15 minutes for 2 to 3 years. Capable of holding up to 32,000 data points, it helped prove that salmon used the entire water column from top to bottom on a daily basis. The king that held one tag (perhaps this one) migrated almost 400 feet vertically six times during one 6-hour period, perhaps one of the most shocking behavioral discoveries in the history of salmon research.


Torpedo Divers on Their Own

Run the lure out 50 to 60 feet behind the boat.
          Clip the Torpedo Diver onto the line, tied to a 12" dropper below the Torpedo Fixed Slider Snap Swivel and attach to the line by sliding it through the Dropper Loop Knot. (Other clips can be used.) Let out the amount of line to depth according to the chart provided.
          Place rod in the rod holder or attach to an inline or planer board and send your bait out to the side. You can also bend the directinoal fin to the left or right to steer the Torpedo Diver in the desired direction away from your boat.
          When reeling in slip out the Fixed Slider or unclip the clip attached to the Torpedo Diver and continue to reel in your catch.

April-May 2014

This article appears on our website with kind permission from Great Lakes Angler Magazine.